计算表达式的值并输出，表达式由若干个数字和运算符（只包含加号和减号）构成

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int analysis(char *expression)
{
    int i=0,j=0,n=0,m=0,num=0,sum=0;
    int param_len=strlen(expression);
    char *p=expression;
    char strnum[1024];
    char oper[1024];
    int splnum[1024];
    
    memset(strnum, 0x00, 1024);
    memset(oper, 0x00, 1024);
    for(i=0; i<param_len; i++)
    {
        if(p[i] != ‘\0‘)
        {
            if(i == param_len - 1)
            {
                strnum[n] = p[i];
                num = atoi(strnum);
                splnum[m] = num;
                m++;
                break;
            }

            if(p[i] == ‘-‘ || p[i] == ‘+‘)
            {
                n = 0;
                num = atoi(strnum);
                splnum[m] = num;
                oper[m] = p[i];
                m++;
                memset(strnum, 0x00, strlen(strnum)*sizeof(char));
            }
            else
            {
                strnum[n] = p[i];
                n++;
            }
        }
        else
        {
            break;
        }
    }

    sum=splnum[0];
    for(j=0; j<m; j++)
    {
        switch(oper[j])
        {
            case ‘+‘:
                sum += splnum[j+1];
                break;
            case ‘-‘:
                sum -= splnum[j+1];
                break;
            default: 
                break;
        }
    }
    return sum;
}

int main(){
    int a=analysis("100+200-1");
    printf("%d\n", a);
}